This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. (January 2013) (Learn how and when to remove this template message)
In 1905, Mironas participated in the Great Vilnius Seimas and, in 1917, the Vilnius Conference. He was elected to the Council of Lithuania and became its second vice-chairman. Later he left politics and worked as a priest.
After the coup d'état in 1926, he was elected to the 3rd Seimas, and after couple of years again returned to priesthood. 1938 he was offered to become the Prime Minister of Lithuania representing Lithuanian Nationalists Union. In 1941 he was arrested and imprisoned, being freed a few days later by the Lithuanian Activist Front. Arrested again in 1945, he was forced to collaborate with NKVD and worked in Vilnius. As his collaboration with NKVD proved not to be satisfactory, Mironas was arrested yet again in 1947 and subsequently sent to Vladimir Prison, where he died in 1953.